MicroRNA profile in site-specific head and neck squamous cell cancer

MicroRNAs (miRs) are non-coding RNA molecules regulating diverse cellular processes essential in carcinogenesis. Little is known regarding miRs in head and neck squamous cell cancer (HNSCC). The aim of the present study was to investigate miRs in relation to the clinico pathological features of site-specific HNSCC.

The study comprised of 51 patients with HNSCC (23 oropharyngeal, 24 laryngeal and 4 hypopharyngeal carcinomas). Total RNA was extracted from tumor tissue and normal squamous epithelium using the miRNeasy FFPE Kit. A quantitative estimation of let-7a, miR-21, miR-200c, miR-34a, miR-375 was performed by a real-time polymerase chain reaction (PCR) method using the TagMan® MicroRNA assay. Additionally, p16 expression was detected by immuno histo chemistry.

Significant differences of let-7a, miR-200c, miR-34a levels between oropharyngeal and laryngeal cancers were found (p<0.05). Compared to non-neoplastic tissues, miR-21, miR-200c, miR-34a were up-regulated and miR-375 was down-regulated in tumors of all sites. MiR-34a tumor levels significantly correlated with oropharyngeal origin (p=0.0284) and p16 positivity (p=0.0218).

The microRNA profile seems to play a potential role in the pathobiology of oropharyngeal and laryngeal HNSCC. Up-regulation of miR34a in p16-positive oropharyngeal cancer has not been so far described and additional studies are warranted.